Not applicable.
1. Field of the Invention
The embodiments disclosed in the specification are directed to increasing the efficiency of data transfer in pulse telemetry systems. More particularly, the embodiments disclosed are directed to an encoding system that increases the bit transfer rate in mud pulse telemetry systems.
2. Background of the Invention
Mud pulse telemetry is used to communicate information from downhole devices to the surface during drilling. This information may include measuring-while-drilling (MWD) information (direction and orientation of the bottomhole assembly, downhole pressure, borehole characteristics, and the like), as well as logging-while-drilling (LWD) information regarding the surrounding formation (electromagnetic wave resistivity, gamma ray, density, and the like).
The communication medium for mud pulse telemetry is the column of drilling fluid within the drill string. The primary purpose of the drilling fluid, however, is not to facilitate data communications, but is to provide adequate downhole pressure to prevent blow-outs, to cool and lubricate the drill bit, and to carry cuttings to the surface. To facilitate the primary purposes, the drilling fluid is pumped into the drill string at high pressure, which causes pressure fluctuationsxe2x80x94noise. Further, the downhole environment generates significant noise in the column of drilling fluid. These factors make data communications using pressure pulses imparted to the drilling fluid difficult.
The oil field services industry is always looking for ways to increase the data transmission rate of information from downhole to the surface.
The problems noted above are solved in large part by a method and related system that increases data transfer efficiency. More particularly, the specification discloses transfer of data by selectively splitting the data into a particular number of bits (for example an eight bit number may be split into two four bit numbers) and sending the data to the surface into smaller groupings, creating shorter transfer times. Further, the specification discloses an increased number of parity values, which may be used to detect and correct errors.
The disclosed devices and methods comprise a combination of features and advantages which enable it to overcome the deficiencies of the prior art devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings.